This work investigates various commercially available austenitic stainless steels and Ni-based alloys as possible metallic bipolar plates for high-temperature polymer electrolyte fuel cells (HT-PEFCs). The dynamic formation and depletion of passivation layers that depends strongly on applied potential was analyzed in 85 wt% phosphoric acid at RT and 130. C by means of cyclic voltammetry and steady-state polarization. All materials showed a beneficial passivation in the potential window 0.3-1.2 V, which is mainly based on a stable inner Cr2O3 layer, and a reduction of the passive layers at cathodic polarization. Alloy 2.4869 (Cronix 80) with 80 wt% Ni and 20 wt% Cr reveals the lowest corrosion rates of 16.1 mu A cm(-2) at 130 degrees C in the passive region at 0.6 V and a free corrosion potential Ecor of 235mV. The improvement of passivity was achieved by the dominant superficial Ni-3(PO4)(2) layer. Alloying additions Mo and Ti revealed a characteristic increase of passive current densities due to instability of these passivation components at 130 degrees C. Passivation based on Fe oxides and phosphates in stainless steels shows to be beneficial at RT, but less efficient at 130 degrees C. (C) 2014 The Electrochemical Society. All rights reserved.